16 October 2018
Slides at ajrominger.github.io/talks

Biodiversity


Biodiversity suports human life

Millennium Assessment Board (2005). Millennium Ecosystem Assessment

Open questions

  • How much biodiversity is requiered to provision services?
  • How does the current extinction rate compare to background extinction?
  • Are changes to biodiversity largely reversible or irriversible?
  • Is the biodiversity in any given ecosystem in equilibrium or not?
  • How severe is the trade-off between human use of natural resources versus biodiversity?

Biodiversity and ecosystem function

Diversity begets productivity

Reviewed in Duffy (2009) Front. Ecol. Environ.

Biodiversity and ecosystem function

Diversity begets stability

Reviewed in Duffy (2009) Front. Ecol. Environ.

Biodiversity and ecosystem function

Millennium Assessment Board (2005). Millennium Ecosystem Assessment

Biodiversity and ecosystem function

Millennium Assessment Board (2005). Millennium Ecosystem Assessment

Biodiversity and ecosystem function

Are we irreversibly altering biodiversity and ecosystems?

Barnosky et al. (2012). Nature

Biodiversity and ecosystem function

Are we irreversibly altering biodiversity and ecosystems?

40% land conversion globally

Barnosky et al. (2012) Nature; Foley et al. (2005) Nature

Area and isolation

A long precedent for viewing habitat fragments as islands

Diamond et al. (1976) Science

Area and isolation

Equilibrium island biogeography theory

MacArthur & Wilson (1976) The theory of island biogeography

Area and isolation

Equilibrium island biogeography theory

MacArthur & Wilson (1976) The theory of island biogeography

Area and isolation

Equilibrium island biogeography theory

MacArthur & Wilson (1976) The theory of island biogeography

Area and isolation

Human activity: direct conversion

Area and isolation

Human activity: climate change

Area and isolation

Human activity: climate change

Area and extinction

Species area relationship \(\hat{S} = f(A)\)

Area and extinction

Species extinctions: \(\hat{S}_\text{new} = \hat{S}(A_\text{orig} - A_\text{loss})\)

\(\Rightarrow \hat{S}_\text{extinct} = \hat{S}(A_\text{orig}) - \hat{S}(A_\text{orig} - A_\text{loss})\)

Area and extinction

Species extinctions: \(\hat{S}_\text{new} = \hat{S}(A_\text{orig} - A_\text{loss})\)

\(\Rightarrow \hat{S}_\text{extinct} = \hat{S}(A_\text{orig}) - \hat{S}(A_\text{orig} - A_\text{loss})\)

Area and extinction


  • Assumes:
    • 200 bird species
    • \(S = cA^{0.25}\)
  • Predicts 32 extinctions
  • 4 extinctions observed

Where are all the extinctions?

Where are all the extinctions?

Extinction debt

MacArthur & Wilson (1976) The theory of island biogeography

Where are all the extinctions?

Extinction debt

Reviewed in Kuussaari et al. (2009) TREE

Where are all the extinctions?

Extinction debt: species interactions





Extinct in 26,600 years

Doughty et al. (2016) Ecography

Where are all the extinctions?

Spatial configuration

Where are all the extinctions?

False dichotomy between social and natural systems

Ecosystems used by humans are not devoid of biodiversity

Where are all the extinctions?

False dichotomy between social and natural systems

Ecosystems used by humans are not inhospitable "oceans"

Where are all the extinctions?

Especially when human use is diverse

Mendenhall et al. (2014) Nature

Where are all the extinctions?

Especially when human use is diverse

Mendenhall et al. (2014) Nature

Biodiversity and human life

Millennium Assessment Board (2005). Millennium Ecosystem Assessment

Biodiversity and human life

What would a minimum model of human demographics and biodiversity feedbacks look like?

Bibliography and useful readings